A compromise between the United States and New Zealand could create the world's largest marine protected area in the Ross Sea.

But it has disappointed the Kiwi filmmaker of The Last Ocean.

The joint proposal, agreed at the weekend after New Zealand horrified conservation groups by breaking away from a previous one, has been put to an international commission meeting in Hobart this week.

A spokeswoman for Foreign Affairs Minister Murray McCully said the agreement would require approval from the other 23 members of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

But the deal reportedly involves a 2.27 million sq km marine protected area, including a 1.6 million sq km designated no-take zone and a "special research zone" allowing "light" fishing and tagging.

New Zealand CCAMLR commissioner Carolyn Schwalger said the proposal struck a "very good balance" between conservation and sustainable fishing.

By last year's catch of 730 tonnes, the toothfish industry in the Ross Sea has a $20 million export value to New Zealand companies.

But Peter Young, whose documentary The Last Ocean chronicles the race to stop commercial fishing in the Ross Sea, felt banning all fishing in the sea was a "no-brainer".

"For someone who wanted to protect the entire Ross Sea, this is a victory for the fishing industry and a defeat for common sense," he told the Herald last night.

"It's really crucial that we do protect the Ross Sea as much as we can, and I would just urge the members of CCAMLR to think about future generations."

Green MP Gareth Hughes said while a proposal was promising, he wanted to see more detail on its research zone.

"What we don't want to see is a backdoor way for commercial fishing to continue under the guise of science."

He was also disappointed the no-take zone would comprise 1.6 million sq km, an area smaller than the zones in each of the initial proposals put forward by the two countries.

Antarctic Ocean Alliance director Stephen Campbell said if specific areas were not protected, the proposal would "fall short of what scientists say is needed to protect key ecosystems in the most pristine ocean left on Earth".